A Honeywell smart thermostat is an excellent way to fine-tune how you use your home comfort system. But like any mechanical system, you might sometimes run into a problem. With a digital display, Honeywell smart thermostats can display an error code that trained technicians can use to figure out what's happening. Here are several of the most likely error codes you could see on your Honeywell smart thermostat.
Error Code e42 for Honeywell Thermostats
You may receive this error code if your home’s Wi-Fi internet did not present an IP address for the thermostat to connect with. This can take place if your router doesn't complete the Dynamic Host Configuration Protocol, or DHCP. This function automatically supplies the required IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can resolve error code e42 by making sure that your router has enabled DHCP. Assuming it does, you may also need to power cycle the router and repeat the initial setup process with your thermostat. Doing so should ensure the DHCP is delivered and connects to your smart thermostat.
Error Code e02 for Honeywell Thermostats
Error code e02 is displayed whenever the password for accessing your home’s Wi-Fi router is incorrect. When this error code has appeared for 30 seconds, the thermostat’s digital display will automatically progress to the Wi-Fi setup screen so you can try to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you need to do to resolve error e02 is make sure you’re typing the correct Wi-Fi password when configuring the thermostat.
Honeywell Thermostat Error 40
Error code 40 can appear when the thermostat is alerted that a heat pump or air conditioner’s monitoring system has recognized a malfunction. Most often, this appears if the compressor isn’t running despite being instructed to. But this error code could also show up if power is disconnected from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, induced by poor airflow, can render this error code. Lastly, you may encounter error code 40 if there’s something wrong with the coolant, the outdoor unit’s fan motor or the motor’s starting capacitor.
How to Fix Honeywell Thermostat Error 40
You can check the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for normal operation. If you restart the thermostat and error code 40 reappears, you should try to get a hold of an experienced technician.
Error Code e43 for Honeywell Thermostats
If the Honeywell thermostat presents error code e43, it is failing to communicate with the router, and by extension the Wi-Fi. This can happen if the router’s ethernet cable isn’t plugged in or it isn’t communicating with your wide area network (WAN).
How to Fix Honeywell Thermostat Error e43
Restart the router by unplugging it and leaving it that way for around 30 seconds. The thermostat might also be disconnected if you have recently switched the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Error Code e1
Thermostats employ sensors to detect the temperature outdoors and indoors. If a sensor fails, you could notice error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can replace the sensor and reboot the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear when the thermostat is unable to detect a heating or cooling unit. This can mean that the equipment itself is faulty and unable to communicate with the thermostat. This can happen when the wiring is defective or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can utilize a voltmeter to find out if there’s a bad electrical connection. If the wiring on your existing HVAC system is bad, the technician can replace it. When the thermostat itself is the source of the error code, it will likely have to be replaced.
Honeywell Error Code e2
If you’ve noticed error code e2 pop up on your Honeywell smart thermostat, it could mean a couple of different things. Sometimes, one of the sensors responsible for detecting the temperature isn’t operating like it should. In other cases, it means the router was disconnected from power before the thermostat could complete the setup process.
How to Fix Honeywell Thermostat Error e2
When the error code is caused by sensor failure, a technician will troubleshoot and swap out the affected sensor. When the problem comes from disconnected power, all you have to do is verify the router remains on throughout the setup process.